Theater-curtain-operating mechanism



W. LEIVILE. THEATER CURTAIN OPERATING MECHANISM.

19349660 APPLICATION Fl' D NOV. 28, I919. 1L1,

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THEATER CURTAIN OPERATING MECHANISM.

APPLICATION FILED NOV. 28. 1919.

1,340,066; P emed M y 11,1920.

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THEATER CURTAIN OPERATING MECHANISM.

APPLICATION FILED NOV. 28, I9I9.

1,340,066, Patented May 11,1920

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i APPLICATION FILED NOV. 28, 1919. v

Patented May 11, 1920.

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WILLIAM LEMLE, OF CHICAGO, ILLINOIS.

THEATEBrGURTAIN-OPERA'IING MECHANISM.

Specification of Letters latent.

Patented May 11, 1920.

Application filed November 28, 1919. Serial No. 341,281.

To all whom it may concern:

Be it known that I, WILLIAM LEMLE, citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in T heater-Curtain-Operating Mechanism; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to mechanisms for raising and lowering screens,curtains or the like, and more particularly to mechanisms adapted to be operated by simple and conveniently located switching means which may be at considerable distance from the curtain or screen. In one of its commercial embodiments, my invention relates to the raising and lowering of screens or curtains for use in theaters, and aims to provide electric-ally' operated means for quickly and positively raising or lowering the screen or curtain; to provide simple and effective counterbalancing means for reducing the required amount of power; to provide simple and effective means for automatically and accurately stopping the mechanism when the screen or curtain has reached either end of its desired travel; to provide simple means for controlling the electrical mechanism by one or more sets of push buttons; toprovide simple means for disconnecting the electrical drive from the mechanism, so as to permit the raising or lowering effected by hand; and to provide simple means for tensioning the operating mechanism and for maintaining the tension uniform at all times.

' In theaters presenting'motion pictures, it is often customary to alternate such pictures with stage performances or with the presentation of display curtains during the rendering of musical selections, which ourtains sometimes carry advertisements. In

either case, it is essential that the curtains, screens or drops should be raised or lowered speedily and effectively, which cannot ordinarily be accomplished after the manner customary in regular theaters, since motion picture theaters do not'employ stage hands. As a substitute for such stage hands, my invention aims to provide an automatic curtain or screen-operating mechanism which can readily be. operated from a distant point by the mere pressing of push buttons, and

which will therefore enable a musician or the operator of the motion picture machine to control the curtains or screens. Illustrative of my invention, though not intended to show the only desirable embodiments of the same, I ampresenting drawings showing several highly desirable methods of carrying out 'my invention, from which drawings (together with the following description) further and more detailed objects of my invention will also be apparent, l

In the drawings, Figure 1 is a partly diagrammatic perspective view showing the general arrangement of mechanism embodying my lnvention as used in connection with a drop curtain.

Fig. 2 is an enlarged elevation of the part of the mechanism disposed below the stage.

Fig. 3 is a view of the same parts, taken at right angles to Fig. 2 and from the righthand side of the latter.

Fig. 4: is a vertical sectionthrough one of method of connecting the mechanism of my invention to the same.

Fig. 7 is a rear view of a pair of curtains, showing how the mechanism of my invention can be connected for laterally draping these curtains. V

In" the diagrammatic view of Fig. 1, I have shown my invention as used in connection with an ordinary type of drop curtain 1 supported by cords 2 running over suitable pulleys 3 and jointly connected to an endless chain or link belt/1. This endless chain is guided at its upper and lower ends respectively by sprocket wheels 5 and.6, the latter sprocket being fast upon a sleeve 7 which is slidable upon ashaft 8 and which is normally coupled to this shaft 8 by a clutch 9. Fast upon the shaft 8 is a worm wheel 10 meshing'with a worm 11 on the shaft 12 of an electric motor 13. Thus'ar I the direction of the motor is reversed, the

endless chain will move in the opposite direction and the curtain will therefore be lowered. To start the motor, I provide an electric relay system which may be operated from distant push buttons 14 placed at any positions convenient to employees of the establishment, so that the operation of the motor can be controlled from these distant points through the electric control box 15 as hereafter more fully described.

To prevent an excessive movement of the chain 4 in either direction, I provide automatic means for shutting off the current at the desired time, so that the operator only needs to push one of the buttons for starting the motor, after which my mechanism automatically attends to the stopping of the motor (and therefore to the movement of the curtain or curtains) at the proper time. To effect this automatic stopping, I provide the'motor driven shaft 8 with an extension threaded to fit a trip arm 17 which arm is guided against rotation by means hereafter described. Disposed in the path of this trip arm 17 are a pair of limit switches 18 and 19' which are electrically connected to portions of the electrical control mechanism shown diagrammatically in Fig. 4. Consequently, when the motor is running in one direction and therefore correspondingly rotating the drive shaft 8, the trip arm 1 I will gradually move along the threaded part of the shaft until it engages the lever 19, thereby opening one of the limit switches and shutting off the supply of current from the motor. Likewise, when the motor moves in the opposite direction, the trip arm will move toward the contact 18 and on engagement with the latter will disconnect the supply of current from the motor. For this purpose I may employ pivoted switch levers each arranged for normally closing the circuit (as shown in Fig. 4) and each normally held in its closing position by a spring 20. Likewise, I desirably provide a suitable guide 21 (as shown in Fig. 3) for affording a sliding engagement with a part of the arm 17 to prevent the latter from being rotated by the' threaded stem 16 through its frictional engagement with the latter.

To compensate for the weight of the curtain 1, I desirably interpose a counterweight 22 in the endless chain 4, and also desirably provide a turn buckle 23 for enabling this chain to be kept sufliciently taut for a proper interlocking withthe sprockets 5 and 6, without unduly tensioning the chain. Thus arranged, the use of a link chain engaging a sprocket which normally is in rigid connection with the drive shaft 8 prevents any slipping of the substantially endless member 4 with respect to the drive shaft. Consequently, I avoid the slipping commonly met when using ordinary cords or cables and am therefore able to stop both the upward and the downward movement of the curtain with an accuracy not heretofore attained. mountings for the contacts 18 and 19, as by clamping these mountings on the bar 24 of Fig. 3, thereby permitting me to adjust the position of these contacts 18 and 19 so as to insure the upward and downward stopping of the curtain at exactly the desired points.

To prevent the cords 2 from exerting a lateral strain on the chain 4, I desirably guide these toward their connection with this chain by sheaves 38 mounted on axles substantially at-right angles to the axis of the sprocket 5, these sheaves being so disposed that the stretches 2 of the said cords (or the cord portions between the sheaves and the part of the endless member to which they are connected) are substantially in the same medial plane with both vertical stretches of the chain 4. That is to say, I guide the various cords to substantially a single point on the endless chain by sheaves which are substantially coaxial and which have their axes spaced by substantially half the diameter of the sheaves from the medial plane of the chain. I also desirably guide the counterweight 22 by suitable means, such as taut rods 31 extending through projecting eyes on the weight as shown in Fig.

1, so as to prevent this counterweight from swaying and thereby shifting one stretch of the endless chain out of the predetermined plane of the latter. Consequently, the tautness of the cords will not cause these to draw the chain more and more to one side while the curtain is being lowered, so that I avoid the undue tensioning which would otherwise occur.

lVhile the arrangement as above described enables the operator to effect the raising and lowering of the curtain automatically, occasions might arise where the interruption of the curtain, or some .faulty operation of the motor, would interfere with the normal operation of my mechanism. In this event the presence of the worm drive would make it impractical to operate the chain 4 by hand if left connected to the drive shaft 8. I therefore do not fasten the sprocket 6 directly to the shaft 8, but connect it to the latter through a clutch which has one jaw fast with respect to the sprocket and has the interlocking companion jaw 9 fast upon the shaft 8. This companion jaw is normally drawn into its interlocking relation by a spring 25 connected to a lever 27 which lever is connected to a collar on the sleeve 7 which carries the sprocket 6, so that the tension of the spring 25 will unlatch the clutch and will therefore permit the chain 4 to be moved by hand for raising or lowering the curtain. To prevent an accidental Then I also provide slidable movement of the lever by engagement with the same, I desirably lock this normally in its clutch-engagin position by suitable means such as a ap 28 forming a hinge part of the floor 29 throu h which the lever 27 extends as shown in ig. 3, and desir ably also provide a companion flap 33 by means of which the lever may be held in its clutch-disengaging position when desired.

Moreover,'the raising and lowering of the curtain need not be limited to its extreme range of movement, as it may sometimes be desirable to stop the curtain at some intermediate point. I therefore desirably employ an electrical remote control arrangement employing pushbuttons arranged in groups of threes, with the connections so made that one button effects the raisin and another the lowering of the curtain, whi e the third button may be pressed for halting the curtain at any desired point intermediate of its normal range of travel. These connections can be made after the general manner shown in Fig. 5 and need not hereby be described in detail, as remote control apparatus taken by itself is not new.

However, while I have heretofore described my invention as employed in the raising and lowering of drop curtains, and as including certain desirable forms of parts, I do not wish to be limited eitherto this particular use of my invention, nor to the details of construction and arrangement here described. Obviously, many modifications may be made without departing from the spirit of my invention. For example, Fig. 6 shows the upper sprocket 5 as connected by a belt 34 to a drum, and as having a laterally separable pair of curtains 35 connected to cords 36 wrapped around the drum, so that these cords will pull the curtains apart when the drum rotates in one direction and will draw them shut when the drum rotates in the reverse direction. Likewise, Fig. 7 shows cords 2 guided for laterally draping back a pair of curtains, which curtains in this case would have theirv lower edges weighted so as to be returned to their closed positions when the pull on the cords 2 is relaxed by a corresponding movement of the chain 4, the latter being connected to the cords 2 after the manner of Fig. 1.

Furthermore, I do not depend entirely on a direct manipulating of the chain 4 if the curtain is to be moved when the motor is stopped and the clutch is unlatched. In practice, this chain is desirably greased to make its action noiseless, and the greasiness makes it undesirable to handle the chain directly. I therefore provide an auxiliary flexible member such as a hand rope 38 connected by hooks 35 to the opposite stretches of the chain 4 and tensioned over a pulley 36 (supported by suitable means not shown in Fig. 1) so that this clean rope can be han-' dled for manually raising or lowering the curtain.

I claim as my invention: v

1. In a curtain operating mechanism, an endless chain, cords connecting a single portion of the chain with various parts of the curtain, and sheaves guiding the respective cords from their said connections to the chain, the sheaves having substantially c0- axial shafts all spaced by substantially half the diameter of the sheavesfrom the medial plane of the endless chain, whereby the portions of the cords leading from the sheaves to the chain are continuously disposed substantially in the same plane with the chain.

2. In a curtain operating mechanism, a pair of sprockets, an endless chain stretched over the sprockets, power means for rotating one of the sprockets, a plurality of cords connected to the chain and arranged for raising the curtain, and a counterweight forming a substantial part of the endless chain and proportioned for counterbalancing the weight of the curtain.

8. In a curtain operating mechanism, a pair of sprockets, an endless chain stretched over the sprockets, power means for rotat-. ing one of the sprockets, a plurality of cords connected to the chain and arranged for raising the curtain, and means for guiding the cords to their connections with the chain, the said guide means being so arranged that the portions of the cords between the guide means and the chain are disposed substantially in the same plane with the entire endless chain. I

4. In a curtain operating mechanism, a pair of sprockets, an endless chain stretched over the sprockets, power means for rotating one of the sprockets, a plurality of cords connected to the chain and arranged for raising the curtain and sheaves for guiding the cords to their connections with the chain, the said guide sheaves being disposed with their axes substantially at right angles to and between the axes of the sprockets, and -the axes of the sheaves being so disposed as to bring guided portions of the cords substantially into the same "plane with the chain.

5. In a theater curtain operating mechanism, a pair of sprockets disposed respectively above and below the floor of the theater, an endless chainstretched over the sprockets, power means disposed below the said floor, cords connecting the chain with the curtain, a clutch releasably connecting the power means with the lower sprocket; a

path of the trip-arm for effecting a stopping of the power means when the last named sprocket has made a predetermined number 10 of rotations.

Signed at Chicago, Illinois, November WILLIAM LEMLE. 

